1These swaging tool drill bit set is made from quality bearing steel, which is sturdy and durable. 2This tool can preserves copper aluminum malleability while doing the swaging, avoiding cracks and leakages. 3When the air conditioner is installed, the copper pipe expands and connects the two copper pipes to each other. 4Suitable for the expansion of copper and aluminum pipes, with a variety of sizes to choose from. 5These swaging tool drill bits are convenient and practical for pipe expansion, and has a wide range of uses. Item Type: Swaging Tool Drill Bit Set Material: Bearing Steel Purpose: Tube Expander Colour: Black System: Inch Expander Size: Approx. 7 or 8 (22.2mm or 0.87in), 3 or 4 (19mm or 0.74in), 5 or 8 (15.9mm or 0.62in), 1 or 2 (12.7mm or 0.5in), 3 or 8 (9.5mm or 0.37in), 1 or 4 (6.3mm or 0.24in) ) Expander Height: 7 or 8 and 3 or 4 Are 5.5cm, 5 or 8 and 1 or 2 Are 5cm, 3 or 8 and 1 or 4 Are 4.5cm 6 x Swaging Tool Drill Bit Set To be used in conjunction with the specified pistol drill. Do not use it outside the required voltage and speed range.